scholarly journals Synthesis of silicon quantum dots using chitosan as a novel reductor agent

2021 ◽  
Vol 67 (2 Mar-Apr) ◽  
pp. 249
Author(s):  
P. A. Hernández-Abril ◽  
J. L. Iriqui-Razcón ◽  
E. León-Sarabia ◽  
S. D. Leal-Soto ◽  
M. E. Álvarez-Ramos ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Synthesis Method ◽  
Blue Emission ◽  
Hydrodynamic Diameter ◽  
Silicon Quantum Dots ◽  
Blue Emission Band ◽  
Water Dispersible ◽  
Chromaticity Coordinates ◽  
Low Molecular Weight Chitosan ◽  
Potential Applications

In the present paper we report a novel synthesis method of silicon quantum dots (SiQDs) using 3-Aminopropyltriethoxysilane (APTES) as silicon precursor and low molecular weight chitosan (CS) as reducing agent. The obtained SiQDs have a hydrodynamic diameter of 2.3 nm, water dispersible, presents blue emission band at 434.5 nm (2.85 eV) with a Commission Internationale de l’Eclairage 1931 (CIE1931) chromaticity coordinates (x = 0.1665, y = 0.1222), the experimental absorbance of the SiQDS was measured and the band gap (Eg) was estimated through PerkinElmer’s method, the obtained value was 3.1 eV and a positive ζ-potential of + 35 mV, resulting in photonics, microelectronics, and biotechnological potential applications.

Green emissive water dispersible silicon quantum dots for fluorescent and colorimetric dual mode sensing of curcumin

2021 ◽  
Author(s):  
Congjie Pan ◽  
Qiaoqiao Wen ◽  
Longfei Ma ◽  
Xuezhen Qin ◽  
Suxiang Feng
Keyword(s):  
Quantum Dots ◽  
Active Ingredient ◽  
Curcuma Longa ◽  
Dual Mode ◽  
Pharmacological Activities ◽  
Silicon Quantum Dots ◽  
Water Dispersible ◽  
Biological And Pharmacological Activities

Curcumin, an active ingredient of Curcuma longa, which possesses good biological and pharmacological activities, is effective in treating of many diseases. Developing simple and sensitive methods for detection of curcumin...

scholarly journals Recent Advancements in Doped/Co-Doped Carbon Quantum Dots for Multi-Potential Applications

2019 ◽  
Vol 5 (2) ◽  
pp. 24 ◽  
Author(s):  
Ganeshlenin Kandasamy
Keyword(s):  
Quantum Dots ◽  
Optical Sensors ◽  
Carbon Nanomaterials ◽  
Synthesis Method ◽  
Carbon Quantum Dots ◽  
Carbon Nanodots ◽  
Synthesis Methods ◽  
Sensing Applications ◽  
Potential Applications ◽  
Co Doped

Carbon quantum dots (CQDs)/carbon nanodots are a new class of fluorescent carbon nanomaterials having an approximate size in the range of 2–10 nm. The majority of the reported review articles have discussed about the development of the CQDs (via simple and cost-effective synthesis methods) for use in bio-imaging and chemical-/biological-sensing applications. However, there is a severe lack of consolidated studies on the recently developed CQDs (especially doped/co-doped) that are utilized in different areas of application. Hence, in this review, we have extensively discussed about the recent development in doped and co-doped CQDs (using elements/heteroatoms—e.g., boron (B), fluorine (F), nitrogen (N), sulphur (S), and phosphorous (P)), along with their synthesis method, reaction conditions, and/or quantum yield (QY), and their emerging multi-potential applications including electrical/electronics (such as light emitting diode (LED) and solar cells), fluorescent ink for anti-counterfeiting, optical sensors (for detection of metal ions, drugs, and pesticides/fungicides), gene delivery, and temperature probing.

scholarly journals Water-Soluble Silicon Quantum Dots with Quasi-Blue Emission

2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Yun Wang ◽  
Hao Wang ◽  
Jun Guo ◽  
Jiang Wu ◽  
Li J. Gao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Blue Emission ◽  
Water Soluble ◽  
Silicon Quantum Dots ◽  
Soluble Silicon

One-Pot Microwave Synthesis of Water-Dispersible, Ultraphoto- and pH-Stable, and Highly Fluorescent Silicon Quantum Dots

2011 ◽  
Vol 133 (36) ◽  
pp. 14192-14195 ◽  
Author(s):  
Yao He ◽  
Yiling Zhong ◽  
Fei Peng ◽  
Xinpan Wei ◽  
Yuanyuan Su ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Microwave Synthesis ◽  
Silicon Quantum Dots ◽  
One Pot ◽  
Water Dispersible

Synthesis and Luminescence Properties of a Blue-Emitting Sr3NaLu(PO4)3F:Eu2+ Phosphor

2017 ◽  
Vol 727 ◽  
pp. 623-627 ◽  
Author(s):  
Zai Fa Yang ◽  
Deng Hui Xu ◽  
Xue Dong Gao ◽  
Jiang Nan Du ◽  
Jia Yue Sun
Keyword(s):  
Blue Emission ◽  
Fluorescence Decay ◽  
Ultraviolet Region ◽  
X Ray Diffraction ◽  
Blue Emission Band ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
Chromaticity Coordinates ◽  
Cie Chromaticity ◽  
White Light Emitting Diodes

A novel blue-emitting Sr3NaLu (PO4)3F:Eu2+ phosphor for white light-emitting diodes (w-LEDs) have been successfully prepared via the solid-state reaction. The crystal structure and phase of the prepared phosphors were investigated using X-ray diffraction (XRD). The band gap of Sr3NaLu (PO4)3F was estimated to be about 5.79 eV from the diffuse reflection spectrum. The Sr3NaLu (PO4)3F:0.05Eu2+ phosphor exhibits an intense and broad excitation band ranging from 200 to 450 nm in the near ultraviolet region and produces a bright blue emission band with the CIE chromaticity coordinates of x = 0.133 and y = 0.148 under the excitation of 365 nm, which were ascribed to the 4f-5d transitions of Eu2+. Moreover, the fluorescence decay curves were also investigated in detail. All the results suggest that Sr3NaLu (PO4)3F:Eu2+ might be a promising blue-emitting phosphor used in w-LEDs.

scholarly journals A First-Principle Study of B- and P-Doped Silicon Quantum Dots

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Jieqiong Zeng ◽  
Hong Yu
Keyword(s):  
Quantum Dots ◽  
Energy Gap ◽  
First Principle ◽  
Silicon Quantum Dots ◽  
Tandem Solar Cells ◽  
Impurity Position ◽  
Structural And Electronic Properties ◽  
Potential Applications ◽  
Impurity Doping ◽  
Electronic Densities

Doping of silicon quantum dots (Si QDs) is important for realizing the potential applications of Si QDs in the fields of Si QDs-based all-Si tandem solar cells, thin-film transistors, and optoelectronic devices. Based on the first-principle calculations, structural and electronic properties of hydrogen terminated Si QDs doped with single Boron (B) or phosphorus (P) are investigated. It is found out that the structural distortion induced by impurity doping is related to the impurity characteristic, impurity position, and the QD size according to the structural analysis. The relative energetic stability of Si QDs with a single impurity in different locations has been discussed, too Furthermore, our calculations of the band structure and electronic densities of state (DOS) associated with the considered Si QDs show that impurity doping will introduce impurity states within the energy gap, and spin split occurs for some configurations. A detailed analysis of the influences of impurity position and QD size on the impurity levels has been made, too.

scholarly journals Photothermally Activated Two-Photon Absorption in Ion-Implanted Silicon Quantum Dots in Silica Plates

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
C. Torres-Torres ◽  
J. Bornacelli ◽  
R. Rangel-Rojo ◽  
J. A. García-Merino ◽  
B. Can-Uc ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ultrashort Pulses ◽  
Photon Absorption ◽  
Saturable Absorption ◽  
Silicon Quantum Dots ◽  
Two Photon Absorption ◽  
Two Photon ◽  
All Optical ◽  
Potential Applications ◽  
Silicon Based

The third-order nonlinear infrared and ultraviolet properties exhibited by silicon quantum dots irradiated by ultrashort pulses were studied. The samples were prepared by 1.5 MeV Si+2ion implantation processes in high-purity silica substrates. Femtosecondz-scan measurements conducted at 830 nm wavelength revealed strong self-focusing effects together with two-photon absorption that can be switched to saturable absorption as a function of the input irradiance. Changes in the main physical mechanism responsible for the picosecond absorptive nonlinearity in the sample were also observed at 355 nm, made possible by the assistance of photothermal phenomena. Ultraviolet self-diffraction explorations allowed us to estimate the Kerr effect of the nanostructures. Potential applications for developing all-optical filtering functions performed by silicon-based nanosystems can be considered.

Synthesis and Phase Transfer of Monodisperse Iron Oxide (Fe3O4) Nanocubes

2014 ◽  
Vol 67 (4) ◽  
pp. 663 ◽  
Author(s):  
Melissa R. Dewi ◽  
William M. Skinner ◽  
Thomas Nann
Keyword(s):  
Magnetic Properties ◽  
Iron Oxide ◽  
Phase Transfer ◽  
Synthesis Method ◽  
Superparamagnetic Iron Oxide ◽  
Spherical Particles ◽  
Hydrodynamic Diameter ◽  
Oxide Nanoparticles ◽  
Magnetic Iron Oxide Nanoparticles ◽  
Water Dispersible

Cube-shaped magnetic iron oxide nanoparticles were synthesised and studied with the aim to achieve superior magnetic properties. This study describes a straightforward and simple synthesis method for preparing monodisperse 11–14-nm superparamagnetic iron oxide nanocubes via an ‘effective monomer’ growth mechanism. The as-synthesised nanoparticles are insoluble in water. However, substitution of the non-polar ligands of the particles using a new method that involved an ionic compound generated colloidally stable and water dispersible cube-shaped particles with a very small hydrodynamic diameter. The cubes displayed superior magnetic properties over spherical particles.

A facile high-speed vibration milling method to mass production of water-dispersible silicon quantum dots for long-term cell imaging

RSC Advances ◽  
2015 ◽  
Vol 5 (44) ◽  
pp. 35291-35296 ◽  
Author(s):  
Jiechao Ge ◽  
Pengpeng Chen ◽  
Qingyan Jia ◽  
Weimin Liu ◽  
Hangyue Zhou ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Mass Production ◽  
High Speed ◽  
Cell Imaging ◽  
Silicon Quantum Dots ◽  
Water Dispersible ◽  
Milling Method ◽  
Vibration Milling

A facile HSVM method has been developed for mass production of water-dispersible SiQDs for long-term cell imaging.

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